Ceiling or flooring element of lightweight concrete

ABSTRACT

In a ceiling or flooring element of concrete or lightweight concrete the improvement of providing the underside of the element with a box containing a porous sound insulating material to secure sound insulation. The box may be fixed by means of two side-pieces and two flanges put in grooves in the element.

United States Patent Larsson et a1.

[54] CEILING OR FLOORING ELEMENT OF 1151 3,656,577 1 Apr. 18, 19722,669,114 2/1954 Mills ..52/599 X LIGHTWEIGHT CONCRETE 2,902,854 9/1959Greene... ..18l/33.1 3,074,505 l/1963 Schulz "52/144 X [721 InventIngmar Lam", Orebm; 3,324,967 6/1967 Robinson ..52/145 x Kumla bmhSweden 3,498,405 3/1970 Charpentier ..l8l/33.1 [73] Assigneez lntong AB,Hallabrottet, Sweden FOREIGN PATENTS OR APPLICATIONS 6 [221 Med Dec 19 965,652 2/1969 Germany 52/145 [21] Appl. No: 881,130 1,172,610 10/1958France ..52/599 1,027,491 4/1966 Great Britain ..52/144 [52] us. CL 1 133 G, 52 145 52 599 115,739 1/1946 Sweden ..52/144 [51] Int.Cl..E04b1/86 58 Field 61 Search ..181/33.1, 33.1 1, 33; 52/599, PrimaryExaminer-Robert Ward,

52/144 145 Attorney-Larson, Taylor and Hmds [56] References Cited [5ABSTRACT UNITED STATES PATENTS In a ceiling or flooring element ofconcrete or lightweight concrete the improvement of providing theunderside of the 2,916,909 12/1959 Mlllel ..l81/33.1 figment with a boxcontaining a porous sound insulating 1,231,348 1917 material to securesound insulation. The box may be fixed by 1 1 1 935 9 i 145 means of twoside-pieces and two flanges put in grooves in the 2,014,749 9/1935 Smith..52/144 l m 2,097,892 11/1937 Powell ..181/33.1 2,271,929 2/1942 Venzie..52/145 3 Claims, 5 Drawing Figures M llillll llll 'lllli l lillllllllll'hill] PATENTEDAPR 181912 3 656, 577

Fig.2

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CEILING R FLOORING ELEMENT 0F LIGHTWEIGHT CONCRETE It is already knownnot only to provide floorings ceilings or walls of any material with asound-insulating cladding, made of acoustic plates for instance, butalso to give a sound-insulation to floorings or ceilings made ofconcrete or lightweight concrete by placing layers of some poroussound-insulating material on their undersides. Such insulation,according to a patent granted (Swedish Pat. No. 196 65 l l, is achievedby arranging, on the underside of the ceiling or flooring in question, alayer consisting of flexibly elastic gypsum plates nailed to a woodenframing which plates support a layer of some porous sound-absorbingmaterial, such as mineral wool.

This type of ceiling, however, is rather costly and labourconsumingbecause the mounting of the components of the same requires much timeand the maintaining during that time of spacious scaffolds isobstructing other working moments on the same site.

To avoid the use of scaffolding it has been proposed, alreadey in thefactory to give a sound-insulation to the concrete or lightweightconcrete elements intended for these ceilings and floorings. This isdone by milling out grooves on the undersides of the elements and to putinto these grooves porous sound-insulating strips, or foam rubber.

This type or sound-insulation, too, means some undesirable disadvantagesinasmuch as the milling of grooves over the whole large surface of aconcrete or lightweight concrete element requires rather a costlymachinery. Besides, it is difficult to carry out the surface treatmentof such concrete or lightweight concrete elements in a satisfactory way.

There is, consequently, great need for instance for a soundinsulatinglightweight concrete element, possible to produce in a rational andcheap way and to mount without using building scaffolds.

The present invention relates to a ceiling or flooring element ofconcrete or lightweight concrete totally eliminating the disadvantagesof types earlier known within this technical field. The elementaccording to the invention has a length by many times exceeding itsheight and width and a width greater than its height.

The invention comprises an element of concrete or lightweight concretewith at least one box adjacant to one of the large surfaces of theelement the box having a plane outer plate and two side-pieces forfixing the box in the two long sides of said element, the side-piecesbeing oriented mainly perpendicularly to said plate and further, in thespace between the plane plate, the two side-pieces and the large surfaceof the element a layer of a porous sound-insulating material.

Referring now to the attached drawing a describtion will be given herebelow about some possible embodiments of the invention.

FIG. 1 is a fragmentary perspective view of three mounted elementsaccording to the invention, the bearings of the elements having beenleft out for the sake of clearness.

FIG. 2 4 are vertical cross sections of four different embodiments ofthe invention.

In FIG. 1 fragments of three lightweight concrete elements 10 are shownwhich on their undersides are provided with boxes 11. The boxes 11 havesucha length that between their short ends and the short ends of theelements there is formed a bearing area 12 of prescribed width. Theelements shown on the figure are joined by tongue and groove."

FIG. 2 shows a vertical cross section of one embodiment of theinvention. The box 13 placed on the underside of the element 10 has oneplane plate 14 parallel to the underside of the element, two side-piecesl and 16 oriented perpendicularly to the plane plate, and two flanges 17and 18. The flanges 17 and 18 are intended to support the box 13. Tothat purpose there are in both the long sides of the element thingrooves 19 and 20 milled out, the length of which shall amount at leastto that of the box 13. By means of the flanges the mounting box becomesvery simple. It consists in introducing the flange 17 into the groove19, the plane plate at the same time being kept bent outwards from theunderside of the element. After that, the side-piece 16 IS bent outwardsfrom the long side of the element and is brought upwards until theflange springs into the groove 20.

In the plane plate 14 of the box there are holes 21 for letting in thesound to the space 22 formed by the box and the lower large surface ofthe element.

The space 22 contains a layer 23 of some porous sound-absorbingmaterial, such as mineral wool, woodwool or similar. The thickness ofthe sound-absorbing layer may vary according to what demands are put onthe insulating power. In the example shown, the space 22 is totallyfilled by the sound-absorbing material the maximum sound-insulation thusbeing obtained. The holes provided for letting in the sound may suitablyoccupy at least 10 15 percent of the surface of the plane plate.

The elementshown in FIG. 3 is principally constructed in the same way asthe previously described one. The difference is that the box has beengiven a profile with rounded corners instead of rectangular ones and,further, that the thickness of the sound-absorbing layer 25 is less thanthe distance between the underside of the element and the plane boxplate 26. By placing the layer 25 at some distance from the underside ofthe element 10 an improved sound-insulation is obtained in relation tothe alternative of letting a layer of the same thickness touch theunderside of the element.

The element shown in FIG. 4 is provided with a box 27 the comers ofwhich are chamfered by 45.

FIG. 5, finally, shows an element the box 29 of which is shaped like aU-profile without flanges. The box is fixed to the element by nailing,screwing or gluing.

The boxes shown in the figures are firstly intented to be made fromplastic laminate, slices of that material being formed to the desiredprofiles after heating in steam but the invention is not limited to thatmaterial. The boxes may, advantageously, be made also of sheet-metal,preferably sheetaluminium or similar.

As will be readily understood from the foregoing describtion theinvention involves many important advantages, the greatest one perhapsbeing the possibility of laying sound-insulating lightweight concretefloorings or ceilings without using scaffolding. Further the total costsas well of the production of the insulation as of its mounting arereduced. Last but not least, floorings and ceilings of an aestheticallyappealing shape are obtained.

We claim:

l. A prefabricated sound absorbing ceiling slab unit, comprising aload-bearing continuous body element of lightweight concrete the lengthof which by many times exceeds its width and height and the width ofwhich is greater than its height, said element having a lower, planarsurface and having, along its sides, grooves and tongues forinterconnecting adjacent body elements, a box located under said lowerplanar surface of said body element and connected to said body element,a layer of sound absorbing material resting upon the bottom of said box,the thickness of said sound absorbing layer being less than the distancebetween the bottom of said box and the underside of said body element,said bottom of the box having apertures permitting sound waves topenetrate said sound absorbing layer, said box having two uprightside-pieces the tops of which are flanged inwardly to provide flangesthe sides of said elements including slots milled out in said bodyelement below said grooves and tongues, said flanges engaging in saidslots thereby connecting said box to said body element.

2. A prefabricated sound absorbing ceiling element according to claim 1,wherein said apertures engage l0-l5 percent of the surface of the planeplate.

3. A prefabricated sound absorbing ceiling element according to claim 1,wherein said box is made of plate of plastic laminat

2. A prefabricated sound absorbing ceiling element according to claim 1,wherein said apertures engage 10-15 percent of the surface of the planeplate.
 3. A prefabricated sound absorbing ceiling element according toclaim 1, wherein said box is made of a plate of plastic laminate.